Electric motor driven lubrication supply system shutdown system and method

Abstract

A system and method for controlling lubricant displacement from a lubrication system and a rotating machine includes supplying a gaseous fluid to the lubrication supply system to displace the lubricant. The gaseous fluid is preferentially directed through a first section of the lubrication supply system and to the rotating machine, and is at least inhibited from flowing through a second section of the lubrication supply system. As a result, the gaseous fluid displaces the lubricant in the rotating machine and in the first section of the lubrication supply system, while the second section of the lubrication supply system remains at least substantially full of lubricant.

1 . An aircraft lubrication supply system, comprising:
 a motor coupled to be selectively energized from a power bus and operable, upon being energized, to rotate at a rotational speed and supply a drive force;   a pump having at least a fluid inlet and a fluid outlet, the pump coupled to receive the drive force from the motor and configured, in response thereto, to draw fluid into the fluid inlet from either a lubricant source or a gaseous fluid source, and to discharge the fluid via the fluid outlet;   a fluid supply line coupled to the fluid outlet and configured to supply the fluid discharged from the fluid outlet to a rotating machine;   a fluid bypass line having an inlet and an outlet, the fluid bypass line inlet coupled to the fluid supply line at a first location, the fluid bypass line outlet coupled to the fluid supply line at a second location that is downstream of the first location;   a bypass control valve disposed between the fluid bypass line inlet and the fluid bypass line outlet, the bypass control valve operable to control fluid flow at least through the fluid bypass line; and   a controller configured to couple to the power bus and to receive a machine de-lube signal, the machine de-lube signal indicating that the rotating machine is being de-lubricated, the controller operable, upon receipt of the machine de-lube signal, to:
 (i) controllably energize the motor from the power bus to thereby displace at least a substantial volume of lubricant in the fluid supply line and the rotating machine with fluid from the gaseous fluid source, and 
 (ii) cause the bypass control valve to move to a position that results in the fluid bypass line remaining at least substantially full of lubricant when the at least substantial volume of lubricant is displaced from the fluid supply line and the rotating machine. 
   
   
   
       2 . The system of  claim 1 , wherein the bypass control valve is disposed in the supply line between the first location and the second location. 
   
   
       3 . The system of  claim 1 , wherein the bypass control valve is disposed in the fluid bypass line between the bypass inlet and the fluid bypass line outlet. 
   
   
       4 . The system of  claim 1 , wherein the bypass control valve is responsive to fluid temperature to thereby control fluid flow at least through the fluid bypass line. 
   
   
       5 . The system of  claim 1 , further comprising:
 a heat exchanger coupled to receive fluid flowing in the fluid bypass line and a second fluid flowing in a second fluid system at a flow rate, the heat exchanger configured to allow heat transfer between the fluid flowing in the bypass line and the second fluid.   
   
   
       6 . The system of  claim 5 , wherein the controller, upon receipt of the machine de-lube signal, causes the flow rate of the second fluid to the heat exchanger to vary. 
   
   
       7 . The system of  claim 6 , wherein the controller, upon receipt of the machine de-lube signal, causes the flow rate of the second fluid to the heat exchanger to increase. 
   
   
       8 . The system of  claim 1 , further comprising:
 a de-lube control valve in fluid communication with the pump fluid inlet, the de-lube control valve movable between at least a first position, in which the pump fluid inlet is in fluid communication with the gaseous fluid source, and a second position, in which the pump fluid inlet is not in fluid communication with the gaseous fluid source.   
   
   
       9 . The system of  claim 8 , wherein the de-lube control valve is coupled to receive one or more de-lube valve control signals and is operable, in response thereto, to move to either the first or the second position. 
   
   
       10 . The system of  claim 9 , wherein the controller is further operable, in response to the de-lube signal, to supply a valve control signal that causes the de-lube control valve to move to the second position. 
   
   
       11 . An aircraft lubrication supply system, comprising:
 a motor coupled to be selectively energized from a power bus and operable, upon being energized, to rotate at a rotational speed and supply a drive force;   a pump having at least a fluid inlet and a fluid outlet, the pump coupled to receive the drive force from the motor and configured, in response thereto, to draw fluid into the fluid inlet from either a lubricant source or a gaseous fluid source, and to discharge the fluid via the fluid outlet;   a fluid supply line coupled to the fluid outlet and configured to supply the fluid discharged from the fluid outlet to a rotating machine;   a fluid bypass line having an inlet and an outlet, the fluid bypass line inlet coupled to the fluid supply line at a first location, the fluid bypass line outlet coupled to the fluid supply line at a second location that is downstream of the first location;   a bypass control valve disposed in the fluid supply line between the first location and the second location, the bypass control valve responsive to fluid temperature to control fluid flow through the fluid bypass line; and   a controller configured to couple to the power bus and to receive a machine de-lube signal, the machine de-lube signal indicating that the rotating machine is being de-lubricated, the controller operable, upon receipt of the machine de-lube signal, to:
 (i) controllably energize the motor from the power bus to thereby displace at least a substantial volume of lubricant in the fluid supply line and the rotating machine with fluid from the gaseous fluid source, and 
 (ii) cause the bypass control valve to move to a position that results in the fluid bypass line remaining at least substantially full of lubricant when the at least substantial volume of lubricant is displaced from the fluid supply line and the rotating machine. 
   
   
   
       12 . The system of  claim 11 , further comprising:
 a heat exchanger coupled to receive fluid flowing in the fluid bypass line and a second fluid flowing in a second fluid system at a flow rate, the heat exchanger configured to allow heat transfer between the fluid flowing in the bypass line and the second fluid.   
   
   
       13 . The system of  claim 12 , wherein the controller, upon receipt of the machine de-lube signal, causes the flow rate of the second fluid to the heat exchanger to vary. 
   
   
       14 . The system of  claim 6 , wherein the controller, upon receipt of the machine de-lube signal, causes the flow rate of the second fluid to the heat exchanger to increase. 
   
   
       15 . The system of  claim 1 , further comprising:
 a de-lube control valve in fluid communication with the pump fluid inlet, the de-lube control valve movable between at least a first position, in which the pump fluid inlet is in fluid communication with the gaseous fluid source, and a second position, in which the pump fluid inlet is not in fluid communication with the gaseous fluid source.   
   
   
       16 . A method of removing lubricant from a lubrication supply system and a rotating machine supplied with lubricant by the lubrication supply system, the method comprising the steps of:
 supplying a gaseous fluid to the lubrication supply system to displace the lubricant;   preferentially directing the gaseous fluid through a first section of the lubrication supply system and to the rotating machine, and at least inhibiting the gaseous fluid from flowing through a second section of the lubrication supply system,   whereby the gaseous fluid displaces the lubricant in the rotating machine and in the first section of the lubrication supply system, and the second section of the lubrication supply system remains at least substantially full of lubricant.   
   
   
       17 . The method of  claim 16 , wherein the lubrication supply system includes a control valve that, based on its position, selectively at least inhibits fluid flow through the second section of the lubrication supply system, and wherein the method further comprises:
 positioning the control valve to a position that at least inhibits fluid flow through the second section of the lubrication supply system.   
   
   
       18 . The method of  claim 16 , wherein:
 the control valve is disposed in the first section of the lubrication supply system; and   the step of position the control valve comprises positioning the control valve to an open position.   
   
   
       19 . The method of  claim 16 , wherein
 the control valve is disposed in the second section of the lubrication supply system; and   the step of position the control valve comprises positioning the control valve to a closed position.   
   
   
       20 . The method of  claim 16 , further comprising:
 disposing a heat exchanger in the second section of the lubrication supply system;   flowing fluid in the second section of the lubrication system and a second fluid from a second fluid system through the heat exchanger; and   increasing the flow of the second fluid through the heat exchanger.